A new species of Moenkhausia Eigenmann (Characiformes: Characidae) from the rio Arinos basin, Brazil

• Autor(a) principal: Dagosta,Fernando C. P.
• Data de Publicação: 2016
• Outros Autores: Marinho,Manoela M. F.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Neotropical ichthyology (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200202
• topic: Headwaters; Juruena; Moenkhausia nigromarginata; Moenkhausia rubra; Tapajós

ABSTRACT A new species of Moenkhausia is described from the rio Arinos drainage, rio Tapajós basin, Mato Grosso, Brazil. The new species is diagnosed from all congeners, except M . hemigrammoides , M . nigromarginata , and Moenkhausia rubra by having intense diffuse dark pigmentation on the dorsal and anal fin-rays. The new species can be distinguished from the above mentioned species by the combination of 20-23 branched anal-fin rays, presence of a vertically elongate roughly rectangular humeral spot surpassing the lateral line ventrally, absence of a well-defined black spot on the distal portion of the dorsal fin and lack of a series of longitudinal dark zigzag stripes on body. The new species is herein described along with a report and discussion of a possible connection between the rio Tapajós and rio Paraguay basins, near Diamantino Municipality, Mato Grosso.